UGC 4459’s diffused and disorganised appearance is characteristic of an irregular dwarf galaxy. Lacking a distinctive structure or shape, irregular dwarf galaxies are often chaotic in appearance, with neither a nuclear bulge — a huge, tightly packed central group of stars — nor any trace of spiral arms — regions of stars extending from the centre of the galaxy. Astronomers suspect that some irregular dwarf galaxies were once spiral or elliptical galaxies, but were later deformed by the gravitational pull of nearby objects.

Rich with young blue stars and older red stars, UGC 4459 has a stellar population of several billion. Though seemingly impressive, this is small when compared to the 200 to 400 billion stars in the Milky Way!

Observations with Hubble have shown that because of their low masses, star formation is very low compared to larger galaxies. Only very little of their original gas has been turned into stars. Thus, these small galaxies are interesting to study to better understand primordial environments and the star formation process.